Joan Rivers, still marching to the orchestra

Amid a veritable forest of ficus trees and potted plants, a small orchestra bedecked the stage of the packed North Shore Center for the Performing Arts Tuesday night for the Joan Rivers show. They played the 78-year-old comedian on. And they played the 78-year-old comedian off. That was it. They must have played a total of about 32 bars — maybe two minutes in all.

So what was this all about? A one-woman stimulus package for underemployed musicians? An expensive joke at her own expense? A nod to how this irrepressible comedy pioneer once was in line to become the queen of late-night TV, until she fell afoul of Emperor Carson? Most likely, it was a kind of existential howl declaring that Rivers is still performing and that she just ain't, at this juncture, going out there to taped music. Even on a Tuesday night in Skokie. It would be akin to going out there without her face on.

And the awkward-looking musicians presented an opportunity; she introduced them at the top of the show as the Jerry Sandusky Orchestra. Rivers has long been an adherent of the school that argues that comedy is tragedy plus time. It's just that she prefers to measure time in, oh, seconds.

That face, incidentally, not only looks remarkably youthful (for all of Rivers' shtick on plastic surgery, she is a walking advertisement for its age-reducing properties), it has lost none of its ability to form into myriad physical shapes. That's the paradox of Rivers' onstage persona: She makes herself look grand just so she can screw her face up to make people laugh. No Botox, nothing nice to screw up, no contrast, no joke. Life is the show; the show is the life.

Much of the time, Rivers will say or do something mildly shocking — like impersonating the way a silent Katie Holmes blinks an SOS with her eyes — and then interrupt herself as if reacting defensively to an outraged audience member. If the outraged audience member cannot be found — and by this point, people expect Rivers to push the envelope and tend to go with her outre flow — she simply makes one up. "Oh, oh," she'll say, suddenly getting aggressive, pushing her face into a sneer and putting down her strawman. Then she'll whisk herself away to some other spot on the stage, apparently oblivious to all of the potted greenery.

Few are better than Rivers at needing all of the showbiz validation — the shows, the stories of daughter Melissa and Cher, you likely know it all — while so skillfully signaling that she knows that when they bury her bones, none of it will be coming along. Among her best bit of material Tuesday was the story of going to New Orleans during its hour of need ("What was that city where they all got wet?") and hanging out with celebrities and cameras in a boat. Then the media leave. "Every so often a hand would come out of the water," Rivers said, miming the act of pushing down a drowning man, for want of a camera to document any act of mercy.

This is dark stuff, of course, but it's Rivers' way of attacking the selfishness of the world and, especially, the fake culture that she herself has exploited for so many years. It feels almost like an act of absolution.

You might think it would be her way through the pearly gates, but she seems not to care for an afterlife. "All my friends are dying," she said at one point Tuesday. "People say, 'She's gone to a better place.' I say, 'No she's not. She had a place in the Hamptons.'"

That's a complicated gag, amid several others about the way people treated the aging — all with a Samuel Beckett-like sting. Intriguingly, Rivers never pretends that her show is anything other than quotidian. Her set is less than an hour. She refers constantly to her own act. She pretends to have no idea in what city she is playing. ("Skokie," she says when told, "it has come to this.")

Well, as Rivers well knows, for her it was always this. You get the sense that she wants her audience not to think of themselves as special, but to know that she does one-nighters most nights a week, just as she has for decades. It's high-energy retail with no sell-by date. Most entertainers fear the rote; Rivers embraces it. Her uber text is simple enough: Whatever the world dishes out, life must go on, fast and furious. Perform or die.